There exists a variety of watercraft including hydrofoils. A preferred embodiment of watercraft including a retractable hydrofoil is described in applicant's U.S. Pat. No. 4,715,304 and in the references cited therein.
There exists a general problem of shock absorption in watercraft, which has long ago been solved for land vehicles. In watercraft the hull is directly impacted by surface variations in the water and the impact affects passengers and vehicle operators in the bridge and on the decks of the craft. High speed operation of watercraft of a size and weight which is sensitive to such impacts often results in discomfort and even injury to operators and often requires limitations in operating speeds of watercraft, which would otherwise not be required.